Recent studies have discovered that mineral oil in food grade packaging derived from recycled fibres may be migrating in the liquid and vapour phases through the fibre structure and into the package contents. It has also been found that food grade packaging made from virgin fibres is not immune from this phenomena, particularly if the exterior of the food grade product has been coated or printed with an ink which comprises mineral oil.
There is a concern that the migration of mineral oil to foodstuffs poses a risk to human health. The Joint Expert Committee on Food Additives (JECFA) has recommended a maximum Acceptable Daily Intake (ADI) of medium and low viscosity mineral oils of 0.01 mg/kg.
Solutions have been proposed to address this issue. For example, in Switzerland the use of recycled fibre in food packaging is no longer allowed. However, in many countries the usage of recycled fibres is very high and extensive infrastructure is in place to recycle fibres. Further, the increased use of virgin fibres is environmentally unattractive. The cost is also higher with virgin fibre owing to increased use of water and energy associated with the processing of wood.
Another solution proposed is to reduce or eradicate mineral oils from printing inks or to pre-treat the waste materials to reduce or remove mineral oils prior to re-use. Again, however, this will have the effect of increasing costs.
Another possible solution is to minimize the migration of mineral oil into food through the use of barriers. To date, paper, polyethylene and propylene liners have been found not to work or not to work efficiently. Other proposals include the use of PET and aluminium foil liners. However, the use of such water-vapour impermeable foils may lead to increased germ formation and, further, it is has been suggested that the direct contact of food and aluminium may present other adverse health risks. Moreover, all of these methods suffer from higher costs.
Thus, there is a need for new and improved solutions to the problem of mineral oil migration in food grade packaging. The present invention addresses this need through the provision of a barrier coating composition.